Russian cosmonauts embark on seven-hour spacewalk outside International Space Station to fit cameras that will watch Earth from orbit

It is set to become the most spectacular webcam in existence, beaming back breath-taking live pictures of Earth from the International Space Station, if only they can get it to work.

A pair of Russian cosmonauts had to abandon attempts to the install two UrtheCast cameras on the the outside of the ISS today after running into a series of problems.

Station commander Oleg Kotov and flight engineer Sergey Ryazanskiy hooked up the cameras, which are part of a Canadian commercial project to stream high-definition video from space to subscribers over the Internet.